1. Field of the Invention
This invention relates to a removably mountable reading unit and a recording apparatus on which the reading unit is mountable.
2. Related Background Art
In a conventional serial printer, recording is effected with an ink ribbon cassette of the heat transfer type, the wire dot type or the daisy wheel type or a head cartridge of the ink jet type placed on a carriage reciprocally movable in a direction along a recording medium and differing from the conveyance direction of the recording medium.
There is also a reading printer which functions as a reading apparatus by a reading unit having the reading function, instead of an ink ribbon cassette, being carried on a carriage.
Generally a reading printer is designed such that light is applied from a light source mounted on a reading unit to the surface of an original and a reflected image from the surface of the original is read by a reading sensor by way of a lens or the like, and is so contrived that a carriage is serially reciprocated and each time one line is read, the original is conveyed, whereby the content of one page is read.
In the conventional reading printer described above, during the reading operation from OHP paper, when a light transmitting plastic sheet or thin paper is used, it has sometimes been the case that the unevenness, aperture, color or the like of a printer body such as a platen which is a recording base for paper during recording is read through such original.
Also, it has sometimes been the case that when the platen is stained by the adherence of ink or the like during recording, paper is stained during reading, or when as in the above-described case, the reading operation from OHP paper or thin paper is performed, the stains on the platen are read through such original.